Systems and methods herein generally relate to machines having print engines such as printers and/or copier devices and, more particularly, to printer color management in image/text printing.
One of the major challenges for every organization that produces products is that every product needs utmost visual satisfaction and mostly they are not measured by any suitable statistical parameters. Generally, any colorant and its complementary colorant (or opponent) shouldn't have non-zero values together for a particular color sample. However, present spot color recipes for some print servers do not completely eliminate the opponent colorant in order to produce visually trackable smoothness.
The color gamut of a printer is a multi-dimensional space of a given volume with the axes of the space being set or defined initially by the pigments used in the colorants of the primary colors. Each set of color primaries: red, green, blue (RGB) or cyan, magenta, yellow, and black (CMYK), defines a “color space” that includes all colors that can result from any combination of these primaries. The “color space,” or “color gamut,” may be quite different for different sets of primaries. Typically, a CMYK color gamut falls inside (is smaller than) a RGB color gamut, which means that the eye can detect more colors than a printer can print. In forming multi-color output images on an image-receiving medium, each of the primary colors is transferred to the image-receiving medium in turn. The color gamut is defined by the interaction of the primary colors, and is limited by a total amount of colorant in any combination that can be effectively deposited on the image-receiving medium. In other words, it is not possible to print some colors that can be photographed or displayed on a monitor when using CMYK printing. The color gamut for a particular image forming device and an associated color rendition dictionary (CRD) by which images may be produced by the image forming device is usually stored in metadata with the image forming device. The CRD and associated set of set points programmed into the image forming device, or family of image forming devices, ensures that the color gamut produced by that image forming device covers, as broadly as possible, an available standard color spectrum.
Some printers include an additional housing (sometimes referred to as the fifth color housing, or Xth color housing if more than 5 are enabled) that holds replaceable printing modules (sometimes referred to as a customer replaceable unit (CCU), fifth color module, spot color module, or imaging media cartridge) that are separate from the permanent color printing modules. This allows switching of the replaceable printing modules seamlessly in minutes; however, the fifth colorants (spot colors) are more expensive and used less frequently than the printer's permanent colors.
In multi-colorant applications there are typically colors that are complimentary; that is, they have hue angles that are nearly 180 degrees apart. This is typical since these additional colors are used to extend the 4-color gamut and to produce a color that is outside those reachable using solely CMYK. For example, typical secondary colors, such as a deep red, which is a combination of magenta and yellow, are very hard to reach. The same is often true of green (complementary to magenta) and blue (complementary to yellow). For complementary colors, the presence of both colors tends to produce a neutral hue, so it is not necessary for gamut extension and is violative of the general rule of not making colors that use the complementary colors simultaneously.
Extended gamut colorant destination profiles are designed to use the extended colorant in regions of the color space that cannot be rendered accurately by the main colors alone. The reason why the extended gamut colorant is used in these regions is to facilitate smooth sweeps that progress across the gamut boundary of the main color output to the region(s) requiring the extended gamut colorant for accurate color representation. Since the expensive extended gamut colorant will be used in color regions covered by the main colors, it is desirable not to use the extended gamut colorant if it provides no color gamut advantage versus the main colors alone.